The director's team-up with Olivier Assayas on this persona-swap psychological thriller is not as exciting as it sounds, but could please some long-time fans.

Four years after “Venus in Fur,” Roman Polanski returns with an adaptation of Delphine de Vigan’s “Based on a True Story,” a stylish but ultimately stiff collection of old tropes about writers and their audience, fiction vs. reality, and the Other that becomes you.

Offering little in the way of fresh material and mixing together influences such as “Misery,” “Single White Female,” and Polanski’s own “The Ghost Writer,” this sophisticated French/Polish two-hander is at least a good showcase for the two lead actresses — while the pairing of Polanski and “Personal Shopper” director Olivier Assayas, here solely on scriptwriting duty, does not quite deliver on its promise.

The story of a successful Parisian writer Delphine (Polanski’s wife Emmanuelle Seigner) on the verge of starting her new book, the film opens on a point-of-view shot of the author facing a sea of admirers at a signing event. Beneath a well-constructed facade of control, you can easily sense the anxiety — even before Eva Green makes her entrance as mysterious fan Elle (‘Her’). Although she vanishes as quickly as she appeared, it’s not long before Delphine finds her again at the event’s afterparty, certainly finding her company (a writer herself, “a ghost for the stars”) more appealing than that of publishers and PR people.

Before you know it, they’re meeting for coffee and becoming fast friends. As played by Green, whose eyes draw you in and whose smile is just a little too forced to be entirely real, Elle is the best kind of enigma — elusive and inspiring, assured but comforting. “How do you look this good so early? I never could,” asks Delphine. “You could. Any woman can,” she replies.

Her job is admittedly made easier by Delphine’s confusion about where to take both her life and her career. She wonders what sort of writer she really wants to be, and whether she should dig deeper into her own experience (particularly her relationship with her mother) or make the leap to ambitious but entirely detached subjects.

As their bond deepens, and Alexandre Desplat’s piano score gets increasingly more unsettling, it becomes clear that we’re witnessing a sort of reverse-”Misery,” in which Eva Green insinuates herself in Delphine’s life to influence it from the inside, pushing her with growing intensity to forget about fiction and give her readers the “hidden story she owes them”. Why looking for stories with such a goldmine at her disposal? “Based on a True Story” is at its best right here — the intersection between fan-obsession thriller and persona-swap character study.

It helps that the role of Elle seems tailor-made to cover the various shades of Eva Green’s usual range of personas, from puzzling charmer to evil seductress, dialing it all the way up to unhinged maniac when needed. The color motif associated with her character — the bright red streaks of her lipstick and scarf — is like a visual jolt to the softly-lit interiors of Delphine’s elegant Parisian flat. Slowly but surely, she starts to appear more red herself, with the two women waltzing around each other and trying on different versions of their relationship. Sometimes they’re close friends, sometimes there’s a faint hint of passion, and other times Elle is scolding Delphine while she sits in her children’s bedroom and plays with illustrated books. Seigner’s disoriented, crumpled look is heartbreaking at first as she tries to keep up, and becomes deliciously wicked when she catches on and realizes that writers sometimes have to devour their source of inspiration.

With Assayas’ script touching on every narrative beat you expect it to, this is in many ways a greatest-hits assembly of a very specific sub-genre, always elegant in both dialogue and direction but rarely allowed to break out of its constrictions. There are a few juicy bits verging on absolute silliness, especially with a series of brief dream scenes that include a screaming Eva Green jump-scare popping out of a smartphone, but it’s for the most part a restrained affair. Assayas, who turned digital communication into a terrific tool for suspense in “Personal Shopper,” will have nonetheless nodded approvingly at Polanski’s handling of a certain Facetime videocall here, reaching disturbing, Haneke-worthy levels of tension between the many screens within the frame.

Ultimately, the film’s real redeeming quality could be that, once you peel off a few layers of distorted and exaggerated meta-discourse, it offers a surprisingly candid and astute portrayal of just how traumatic the start of a big new friendship is. Films depicting the progressive convergence of two characters often seem concerned with mirroring romantic attraction, which we are often better equipped to handle. The type of life-altering, out of the blue new friendship that pulls the rug under Delphine’s feet, on the other hand, sneaks up on you in disorienting ways. As a better version of herself, this abstract ‘elle’ is constantly pulling away, daring this woman to become like her while making her wonder if that’s even possible. Sometimes you lose yourself in friendships much more so than in love. And often, as it happens at the end of “Based on a True Story,” the end of it all is so anticlimactic that it leaves you sitting there, in your brand new lipstick, wondering how could it ever have been worth it.

Grade: C+

“Based on a True Story” premiered out of Competition at the 2017 Cannes Film Festival. Sony Pictures Classics has acquired the rights to the film’s U.S. distribution.